result code = -1
standard error = {
tests/diagnostics/parameter-already-defined.slang(4): error 30200: declaration of 'a' conflicts with existing declaration
int foo( int a, float a ) { return 0; }
                      ^
tests/diagnostics/parameter-already-defined.slang(4): note: see previous declaration of 'a'
int foo( int a, float a ) { return 0; }
             ^
}
standard output = {
}